Readily alterable woven-wire magnetic memory unit

ABSTRACT

Woven-wire, transformer memories that are to be occasionally altered by adding conductors to their braid, have an end of each of the legs of their cores extended past a usual U-shaped portion. The end that is extended is readily moved outward momentarily in opposition to a mounting spring to form between the leg and the rest of the core a gap that is wide enough to permit passage of additional conductors for storing information. The conductors to be added are first braided on the extended portions of the legs, and their coding positions are checked before the memory is interrupted only long enough to move the added conductors a short distance along the legs through the gaps.

United States Patent Reimer 1 1 June 20, 1972 [54] READILY ALTERABLE WOVEN-WIRE 3,160,860 12/1964 Henderson ...29/604 x MAGNETIC MEMORY UNIT 3,384,954 5/1968 Bradford et al.. ...29/604 X 3,541,681 1 1/1970 Hauerbach ..29/604 [72] Inventor: William A. Reimer, Wheaton, Ill.

[73] Assignee: GTE Automatic Electric Laboratories ln- Primary Examiner-Sta?! urynowicz'jr' corporaed Northlake L Attorney-K. Mullerheim, B. E. Franz and Robert F. Van

Epps [22] Filed: Dec. 3, 1970 21 App]. No.:. 94,710 [57] ABSTRACT Woven-wire, transformer memories that are to be occasionally altered by adding conductors to their braid, have an [52] US. Cl ...340/174 SP, 340/174 MA,32396/;520l42, end of each of the g of their cores extended p a usual U In Cl G1 1c 5/04 6 1 1c 17/00 shaped portion. The end that is extended is readily moved out- Fieid 4 SP 174 1 174 1 ward momentarily in opposition to a mounting spring to form 336/21 between the leg and the rest of the core a gap that is wide enough to pennit passage of additional conductors for storing information. The conductors to be added are first braided on [56] Reerences Clted the extended portions of the legs, and their coding positions UNITED STATES PATENTS are checked before the memory is interrupted only long enough to move the added conductors a short distance along 3,496,556 2/ 1970 Wennstrom ..340/ 174 SP thelegs through the gaps 1,692,486 11/1928 Cohn Bojarski ..336/212 X 4 Claims, 7 Drawing Figures PATENTEUmzo m2 SHEET 10! 2 INVENTOR WILLIAM A. REIMER iaw/z 44%;

I ATTORNEY FIG. 2

BACKGROUND OF THE INVENTION The invention relates to magnetic memories and particularly to woven-wire, read-only, transformer memories with improved means for adding new information.

A well-known type of element for magnetic memories has a core comprising a U-shaped portion and. a removable leg that fits across the ends of the U-shaped portion to complete a magnetic path. Typically, a single winding is placed on the U- shaped portion of each core of a memory, and a plurality of conductors that are woven into a braid are placed on the legs of a group of successive cores. The conductors of the braid selectively pass through or bypass the cores. The conductors that pass through the cores obviously have a closer magnetic coupling to the single winding of the U-shaped portion than the coupling of the wires that bypass the cores. Customarily, a binary ONE is represented at a core by a wire passing through it, whereas a binary ZERO is represented by a wire passing around it.

A transformer memory having woven conductors and a removable leg is described in US. Pat. No. 3,496,556 issued to Arthur E. Wennstrom on Feb. 17, 1970. As described in that patent, the woven conductors may be the sense windings, and the single windings may be the drive windings. However, in certain applications, such as translators in telephone systems, the woven conductors are the drive windings, and the single windings are the sense windings. Basically, the memory element to which the present improvement is added is similar to the memory element without the loading winding and the shielding means described in the patent to which reference has been made above.

Woven-wire, transformermemories are read-only" memories, and code changes, corresponding to different threading of the conductors of the braid, require disabling the memory over undesirably long periods. In the former memory described above, the legs of the cores are to be removed while certain ones of the conductors threaded through the cores are changed to provide a new code.

SUMMARY OF THE INVENTION A magnetic memory element of the present invention has in addition to the usual area for storing information, a codechange area adjacent to the information area. The information area comprises the usual rectangular core with a U-shaped portion and a removable leg. However, the leg is longer than the distance between the ends of the Ushaped portion, and the end of the leg that extends past the information area defines the code-change area. Preferably, the leg is normally held against the ends of the U-shaped portion by springs. The extension of the leg can be readily moved far enough outward from the end of the core to form a gap wide enough for passage of conductors into the information area. While a memory containing cores of this type is operable, conductors for adding new information are woven on the extended portion of the leg, and the placement of the wires for passing through or bypassing the cores is observed visually or tested electrically. At a convenient time after the wires are placed in the code-change area, the operation of the memory is interrupted only long enough to pull each leg outward and to move the added conductors along the slightly displaced leg from the code-change area to the information area.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is an oblique view of a. group of memory cores to which is added a coding conductor in code-change areas of the cores;

FIG. 2 is a fragmentary cross-section of a memory to show a preferred mounting of the cores and to show conductors in the code-change area of one of the cores;

FIG. 3 is a side view of a core showing its leg moved outward, and the added conductors moved into the information area;

FIG. 4 is a side view of the core of FIG. 3 with its leg returned to its operating position;

FIG. 5 is a side view of a core to show the addition of a verification winding;

FIG. 6 is a side view of a core assembly that has a simple C- shaped portion and an extended leg; and

FIG. 7 is a side view of an I-shaped core having two information areas.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, a conductor 11 is placed in or along a codechange area 12 adjacent an information area 13 in each one of a group of core assemblies 14. A braid 15 of woven conductors is placed on each leg 16. The width of the braid is shorter than the length of the portion of the leg in the information area, and its edge is positioned away from the code-change area to leave room for transferring conductors from the codechange area to a space adjacent the braid in the information area.

The positioning of the conductor 11 along with other conductors l7 and 18 to be positioned in the information area is shown more clearly in FIG. 2. The magnetic core assembly 14 has a modified rectangular U-shaped portion 19 and a leg 16. The short, parallel sides 20 and 21 of the portion 19 define the ends of theinformation area of the core. As described below,

the intermediate portion of the core 19 may be extended beyond the short side 20 into the code-change area to become part of a verification circuit. The leg 16 extends between the short sides 20 and 21 to complete a magnetic path within the core assembly 14, and it has a portion 23 that extends beyond the short side 20 into the code-change area 12.

In FIG. 2, a plurality of core assemblies 14 are shown in a row, one end of each assembly being mounted between parallel, rectangular, mounting bars 24, and the other end being mounted between similar bars 25. Leaf springs 26 and 27 extend slantingly from the bars 24 and 25 respectively to contact the outer side of each leg 16. The long sides of the U-shaped portions 19 contact the bars 24 and 25 at points opposite or nearly opposite the short sides' 20 and 21 respectively. Each assembly is therefore mounted between a pair of bars 24 and 25 on one side and a pair of springs 26 and 27 extending from similar bars on the opposite side, and the springs urge the leg 16 of an assembly 14 against the poles of the short sides 20 and 21. By applying a moderate amount of force to the end 23 v of the leg 16 in opposition to the force applied by the spring 26, the leg 16 is moved outward a short distance from the end of the short side 20.

In FIG. 2, conductors 11, 17, and 18 that are woven on successive legs 16 of a group of core assemblies 14 are shown on one of the legs in the code-change area 12 before the conduc tors are moved into the information area 13. Each of the legs 16 may have a smooth surface or covering on its end to be used for code changes so as to facilitate sliding added conductors into the information area. In FIG. 3, the leg 16 is shown moved outward, the conductors 11 and 17 that pass through the core for a bit ONE have been moved through the space between the end of the short side 20 and the leg 16 into the information area 13, and the conductor 18 that bypasses the core has been moved opposite the area 13. If desired, the bar 24 with spring 26 can be mountednearer the end of the leg than where it is shown so that it may be opposite the short side 20, and any conductor such as the conductor 18 where it bypasses a core assembly 14' need not be moved from the code-change area because the magnetic coupling between the conductor and the core is low in either location. In FIG. 4, force to hold one end of the leg 16 slightly apart from the U- shaped portion 19 has been removed after the code change for the assembly has been made, and the force of the spring 26 has returned the leg to its normal position.

The woven braid 15 that contains the original coding or information may preferably be wound directly on the legs 16 while they are held in the same configuration as they will be placed in an assembled memory. Altemately, the braid may be wound on insulating tubes, and the tubes with the braid assembled to the cores. The amount of space to be left between the edge of the braid l5 and the portion of the leg 16 that contacts the end of the short leg 20 depends on the number of conductors that are to be added subsequently to the information area. As mentioned above, for different applications, the conductors woven in the braid l5 and the single windings 28 that are conveniently placed on the U-shaped portions 19 of the core may be used interchangeably either as drive windings or as sense windings.

In FIG. 5, a removable bar 29 of magnetic material is shown across the ends of the portion of the core 19 and the leg 16 that form the sides of the code-change area 12. Each bar has a winding 30 that can be used in a conventional memory circuit to test whether added conductors are placed as desired to provide a new, wanted code before the added conductors are moved into the information area 13.

The embodiment shown in FIG. 6 has a simple C-shaped or U-shaped portion 31, and unlike the embodiment described above, the intermediate part is not extended for accommodating a bar with a verification winding. However, the leg 32 is extended as described above; also a braid is located on the leg, and a single winding is wound on the C-shaped portion.

The embodiment shown in FIG. 7 uses an l-shaped core 33 with a leg on each side to form two information areas 34 and 35. A braid of coded conductors can be placed on each leg, and conductors can be added above the braids as described above. The single winding 36 is located on the central portion of the core.

lclaim:

1. In a magnetic memory of the type having a plurality of cores arranged in groups, each core having a substantially U- shaped portion and a removable leg, said removable leg extending between the ends of said U-shaped portion to form a complete magnetic path that encloses an information area, a woven braid of a plurality of conductors woven on the successive legs of each of said groups, said conductors passing and bypassing said legs selectively to store infonnation, and an additional winding on said core having mutual coupling with any selected one of said conductors,

each of said cores having a code-change area formed by the extension of at least one end of its leg outside of said complete magnetic path past an adjacent end of its U- shaped core, the portion of each of said legs extending past said respective adjacent end adapted to receive additional conductors in a desired configuration to provide respective new information in addition to the information provided by said conductors of said braid, and the extending end of each of said legs being readily movable a sufficient distance outward from said adjacent end of said U- shaped core to provide enough gap to permit said additional conductors to be moved along said leg from said code-change area to said information area.

2. In a magnetic memory as claimed in claim 1, spring means mounted to urge each of said legs inward against the ends of its U-shaped portion.

3. In a magnetic memory as claimed in claim 1, each of said U-shaped portions having an extension outside said complete magnetic path of said information area, said extension of each of said U-shaped portions forming a side of said code-change area opposite a side formed by the respective one of said extending portions of said legs, a magnetic bar removably positioned between the ends of said sides of said code-change area, and a winding on each of said bars to facilitate the electrical testing of the position of said additional conductors while they are in the code-change area.

4. In a magnetic memory as claimed in claim 1, each of said cores having an additional information area such that the two information areas of each core appear as images of one another, said core therefore having an l-shaped portion to form the two U-shaped portions, the portion of the core between the legs of I-shaped portion being common to the two information areas, and said additional winding being placed on said common portion. 

1. In a magnetic memory of the type having a plurality of cores arranged in groups, each core having a substantially U-shaped portion and a removable leg, said removable leg extending between the ends of said U-shaped portion to form a complete magnetic path that encloses an information area, a woven braid of a plurality of conductors woven on the successive legs of each of said groups, said conductors passing and bypassing said legs selectively to store information, and an additional winding on said core having mutual coupling with any selected one of said conductors, each of said cores having a code-change area formed by the extension of at least one end of its leg outside of said complete magnetic path past an adjacent end of its U-shaped core, the portion of each of said legs extending past said respective adjacent end adapted to receive additional conductors in a desired configuration to provide respective new information in addition to tHe information provided by said conductors of said braid, and the extending end of each of said legs being readily movable a sufficient distance outward from said adjacent end of said U-shaped core to provide enough gap to permit said additional conductors to be moved along said leg from said code-change area to said information area.
 2. In a magnetic memory as claimed in claim 1, spring means mounted to urge each of said legs inward against the ends of its U-shaped portion.
 3. In a magnetic memory as claimed in claim 1, each of said U-shaped portions having an extension outside said complete magnetic path of said information area, said extension of each of said U-shaped portions forming a side of said code-change area opposite a side formed by the respective one of said extending portions of said legs, a magnetic bar removably positioned between the ends of said sides of said code-change area, and a winding on each of said bars to facilitate the electrical testing of the position of said additional conductors while they are in the code-change area.
 4. In a magnetic memory as claimed in claim 1, each of said cores having an additional information area such that the two information areas of each core appear as images of one another, said core therefore having an I-shaped portion to form the two U-shaped portions, the portion of the core between the legs of I-shaped portion being common to the two information areas, and said additional winding being placed on said common portion. 